1. Field of the Invention
The present invention relates to receivers. More specifically, the present invention relates to a receiver for receiving a broadcast in which additional information is multiplexed with main information including audio information (acoustic signal) or video information, such as a digital radio broadcast.
2. Description of the Related Art
Digital radio broadcasting service has already begun in Europe as DAB (Digital Audio Broadcasting) based on Eureka 147, and has been proposed in Japan and the United States.
In digital radio broadcasting, high-quality transmission of audio information such as music can be achieved, and furthermore, additional information associated with a program, such as text data and image files, can be multiplexed and broadcast with the main audio information.
The list of proposed types of additional information includes: (1) information such as ID of broadcasting service (identification information), name of broadcasting station, name of program, category of program; (2) information regarding program content, for example, an artist name and a song title in the case of a music program; (3) timestamp (time-of-day information); and (4) other accompanying information.
In the case of a music program, the accompanying information is, for example, text data showing words of a song broadcast in the program, concert information of an artist on the program, etc. It is also possible, for example, to compress the jacket of a CD including a song broadcast in the program based on JPEG (Joint Photographic Experts Group) format, broadcasting the actual data of the JPEG file and header information indicating a JPEG file as accompanying information constituting part of additional information.
In a receiver for receiving a digital radio broadcast of the type described above, additional information of a received program is displayed on a display such as an LCD (liquid crystal display). Thus, for example, a user listening to a music program is allowed to take notes regarding artist name, song title, and concert information as required with reference to the display, which is useful, for example, in purchasing CDs or concert tickets.
However, if the receiver is implemented as an on-vehicle device, the user is not allowed to watch into the display while driving, or to take notes. Furthermore, if the receiver is implemented as a portable device, in some situations, for example, while walking, the user may not be allowed to watch into the display or to take notes.